1. Field
This disclosure is directed to a wireless communication system and, more particularly, to a method of aperiodically or periodically transmitting a sounding reference signal in a wireless communication system supporting a plurality of component carriers, a base station and user equipment.
2. Discussion of the Background
Current mobile communication systems, such as 3GPP (3rd Generation Partnership Project), LTE (Long Term Evolution), LTE-A (LTE Advanced), and IEEE (The Institute of Electrical and Electronics Engineers) 802.16, are high-speed and high-capacity communication systems capable of transmitting and receiving data, such as video and radio by a voice-based service. In these mobile communication systems, an error detection scheme for technology capable of transmitting a large amount of data complying with a wired communication network, minimized information loss, and improved system transmission efficiency includes certain elements.
Furthermore, in several current communication systems, through uplink and downlink, the use of several types of reference signals for providing information about a communication environment and other information is used.
For example, in the LTE system, a User Equipment (hereinafter referred to as UE) sends a Sounding Reference Signal (hereinafter referred to as an ‘SRS’) (i.e., a reference signal used to estimate an uplink channel state) to an eNB, and an eNB sends a Cell-specific Reference Signal (hereinafter referred to as a ‘CRS’) (i.e., a reference signal used to estimate a downlink channel state) to a UE every subframe.
In addition, reference signals for channel estimation, and so on are periodically generated by, in general, an apparatus for transmitting the reference signals (for example, UE in the case of an uplink reference signal and an eNB in the case of a downlink reference signal).
Unlike a communication system that uses one carrier composed of one frequency band, a scheme capable of using a plurality of Component Carriers (hereinafter referred to as a ‘CC’) is also being explored.
In a communication system using a plurality of CCs, each of the CCs may function as one cell. A detailed scheme for transmitting a channel estimation reference signal for each CC has not yet been defined.